Tube Noise briefing July 2018

This is an issue I have been pursuing vigorously with TfL and I think I have got to the bottom of what has  caused  the relatively recent problems affecting people who had no noise issues for many years before.

It is a combination of factors.

Firstly, TfL renewed the track, replacing the old wooden sleepers with concrete; and the rails with a new flatter profile rail which was fixed directly to the sleeper, with nothing between to deaden noise.

TfL has also automated the trains on the Northern Line, the result of which has been to effect braking and accelerating of the trains at exactly the same point on the rail near stations, as opposed to when trains were driver controlled, so the wear on the rail was spread over a greater distance as each driver would brake etc at different points. The result of this is to increase the wear on the track and consequent ‘corrugation’ of the rail near stations.

They are also running more trains at greater frequency, requiring higher speeds.

All these factors generate more kinetic energy which is manifested by noise and vibration.

TfL have now embarked on a programme of retrofitting what are in effect pads between the rail and the sleeper  to reduce the noise and vibration that is transmitted to the line’s ‘neighbours’ as a first stage in remedial work

This work, though is taking too long in my view and whilst it has it helped, it has had mixed results in some cases.

TfL can retrofit 100m of track a week.

Work has  completed at Mornington Crescent, where it has been going on for several months; there was about 1 km to treat, there.  This has not been as successful as hoped, so further works will be needed.

They are now working near Kentish Town. That work is now expected to be completed towards the end of August.

TfL crews can be called off this work, to do other urgent maintenance ( e.g. a cracked rail replacement) which affects these programmes.

I have raised these delays with the Mayor and TfL, who  have now agreed to my request to hire more staff to engage  in remedial work, as it is  taking too long to address problems: there is now an additional crew of 12 working on these mitigation measures.

TfL prioritise where they do the work, by reference to a combination of the noise levels , the number of complaints from a particular location, and the ease or otherwise of the remedial work that can be done .

I would thus encourage you to encourage any neighbours who are affected also to complain to TfL and to copy me in.

Noise complaints should be made to TfL’s 24/7 Customer Service centre on 0343 222 1234 or at tfl.gov.uk/contact.  Concerns can then be logged, and they will be asked to complete a short questionnaire. TfL will then visit their property, in order for noise readings to be taken. It is important that TfL have a record of every individual noise complaint in an area, even if a neighbour has already complained, as this helps them  determine any hot-spots across the network.

I have just met the new Deputy Mayor for Transport  and held a  Northern Line site visit with TfL to meet with some of the  residents who are affected between Mornington Crescent and  Tufnell Park , which I hope will push TfL along to do the necessary works as quickly as possible.

I also regularly ask questions of the Mayor about the problem: see below for recent answers.

I hope this update is helpful to you, and I will keep you informed of developments.

 

Tube noise [1]

Question No: 2018/1541

Andrew Dismore

Before the concrete sleepers and new track profile began to be installed on all lines, what research, work or other consideration was given to the likely increase in noise generated by these changes, compared to the traditional wooden sleepers and rail profile?

Written response from the Mayor

London Underground has been operating since 1863, and keeping this system moving is a unique challenge. Although there are no legal limits on the amount of noise or vibration that can be emitted from trains operating on existing railways, Transport for London (TfL) is still required to use reasonable endeavours to minimise disturbance and to keep noise and vibration to a minimum, while undertaking their statutory duties.

Where new railways are proposed, noise and vibration are considered as part of the planning process, and mitigation will likely be incorporated into the design to control noise and vibration.

TfL’s understanding of noise and vibration, at the time this type of track renewal started in the mid 2000s, was not as sophisticated as it is now, and the impact on noise and vibration would not have been considered in detail.

The ‘new’ Flat Bottom rail profile, installed on concrete sleepers, is an industry standard, and was initially designed in the 1930s. Compared to the Bullhead rail profile on timber sleepers, the Flat Bottom rail profile delivers a significant increase in safety performance. This is largely as a result of the significant reduction in the risk of rail breaks.

Noise and vibration reduction have been important factors in the development of a new trackform, which has been introduced since 2015. TfL do now consider the impact on noise and vibration prior to carrying out this type of work.

More broadly, TfL understand the importance of minimising noise levels for their neighbours, and is determined to do more to achieve this. I continue to press TfL to carry on actively working with suppliers and academics to innovate and develop new technology to improve noise levels across the network.

 

Tube noise [2]

Question No: 2018/1542

Andrew Dismore

Before train automation went live what research, work or other consideration was given to the likely increase in noise generated by these changes, compared to the traditional driver controlled braking?

Written response from the Mayor

Transport for London’s (TfL’s) understanding of noise and vibration at the time train automation was introduced was not as sophisticated as it is now, and assessing impacts on noise and vibration was not the priority it currently is.

The implementation of automatic train control does not in itself lead to increased noise and vibration, and rail corrugation still occurs where automatic train control is not in place. Automatic train control increases average trains speeds, allowing more trains per hour on the London Underground network, increasing capacity and benefiting customers.

Automatic train control does result in trains consistently braking and accelerating at the same point, which can lead to track deterioration occurring more quickly at these points. Additional trains can also lead to further track deterioration which, if not addressed, could lead to increased noise and vibration over time.

Track condition is addressed by TfL’s regular maintenance programme, which ensures that track is replaced or repaired as appropriate.

 

Tube noise [3]

Question No: 2018/1543

Andrew Dismore

By each line, how many complaints have there been about tube generated noise in the year to date and each of the last 3 years?

Written response from the Mayor

Below figures show the number of noise and vibration complaints, from nearby properties, which relate to the day-to-day running of the Tube network.  The 2018 data is current up to 11 June 2018.

2016

Bakerloo  – 13

Central – 79

District – 38

Hammersmith & City – 11

Jubilee – 26

Metropolitan – 17

Northern – 86
Piccadilly – 24
Victoria – 80
Waterloo & City – 1
Total – 375

 

2017

Bakerloo  – 7

Central – 52

District – 28

Hammersmith & City – 16

Jubilee – 17

Metropolitan – 8

Northern – 90
Piccadilly – 19
Victoria – 77
Waterloo & City – 0
Total – 314

 

2018

Bakerloo  – 1

Central – 20

District – 6

Hammersmith & City – 5

Jubilee – 6

Metropolitan – 0

Northern – 22
Piccadilly – 4
Victoria – 28
Waterloo & City – 0
Total – 92

 

 

Tube noise [4]

Question No: 2018/1544

Andrew Dismore

What progress has there been in obtaining a rail grinding machine that can work in the Northern Line tunnels?

Written response from the Mayor

Transport for London (TfL) has rail grinding machines that operate on the Northern line. However, due to ventilation issues, there are sections of the Tube, on both the Northern line and other parts of the network, where grinding cannot be carried out.

TfL understand the importance of minimising noise levels for their neighbours, and is determined to do more to achieve this. TfL is exploring the possibility of purchasing an electric-powered rail grinder for use across the Tube network, although there would still be areas where ventilation issues would mean grinding cannot be carried out.

Rail grinding is not an effective long-term method for reducing noise and vibration. Grinding is predominantly used to maximise rail life and reduce the risk of rail defects.

 

Tube noise [5]

Question No: 2018/1545

Andrew Dismore

Over the bank holiday weekend, TfL replaced 800 tonnes of old track bed with new granite ballast, installed longer life concrete sleepers and new rail at Finchley Central. What assessment was given to the risks of an increase in tube noise as a result of these works creating a noise nuisance for those living near the line?

Written response from the Mayor

The work at Finchley Central to replace older track has delivered improved safety, a smoother ride for customers and has removed a number of rail joints.

In tunnelled sections of track, wear and tear of the rails can lead to increased vibration, which can then be transmitted further into the ground through concrete sleepers. These issues are not replicated on above ground sections such as at Finchley Central as the vibrational energy is dispersed into the air and not into the surrounding ground.

The work carried out at Finchley Central over the Bank Holiday weekend has resulted in a number of impulsive noise sources being removed and should result in the resolution of some complaints in the area. Transport for London (TfL) is following up with all the individual residents affected to assess whether there has been a reduction in noise.

In tunnelled sections, TfL has applied its knowledge of noise and vibration issues so that all track renewals involving concrete sleepers or bases incorporate resilient elements to reduce the impact of vibration, with no increase to the noise generated within the tunnel.

I’ve asked TfL to arrange for you to view some of this work in action with one of its track teams. Officers will be in touch with you to arrange this.

 

Question tile: Tube noise [6]

Question No: 2018/1546

Andrew Dismore

What consultation with residents was there before the bank holiday works at Finchley Central, about the issue of tube noise as a consequence of the works?

Written response from the Mayor

Transport for London (TfL) is required to use reasonable endeavours to minimise disturbance and to keep noise and vibration to a minimum, while undertaking their statutory duties.

Although TfL is not required to consult residents when upgrading track, permission was sought from the local authority to undertake this work. TfL also informed local residents of the potential for disruption, as is normal. As part of this process, over 3500 letters were delivered to residents advising them of the work and how to contact TfL should they have a query.

 

Tube noise [7]

Question No: 2018/1547

Andrew Dismore

What advice will you give to long standing residents who face relatively recently generated increases in significant tube noise above 40Db after Transport for London have done such mitigation works as they can, and will not do anymore?

Written response from the Mayor

There are many sites across the Underground network where, due to the age of the track infrastructure and current technology, it is not always possible to reduce the noise levels to the standards that residents would like.

Transport for London (TfL) will continue to do all it possibly can to minimise noise and limit disruption to residents living above or close to the Tube.

In areas where noise cannot currently be reduced to standards expected by residents, TfL continue to work alongside industry and academia to further understand noise and vibration and to trial new products and innovative ways to find solutions.

 

Tube noise [8]

Question No: 2018/1548

Andrew Dismore

My constituent Razana Yoosuf of Mornington Crescent first raised her problems with Tube noise on 1 Nov 2016 and, after 19 months, she is still waiting for her complaint to be satisfactorily resolved with many readings exceeding 40DB after mitigation measures were implemented. Do you consider this to be satisfactory; and, if not, what are you going to do about it?

Written response from the Mayor

Transport for London (TfL) has been working closely with Razana Yoosuf in dealing with the noise complaints she has raised.  We have undertaken noise monitoring at her property and have installed 400m of rail damping equipment across three of the four lines at Mornington Crescent.  This has resulted in a reduction of up to 13dB for train movements heard within the property.  TfL has put in place various measures to mitigate noise in this area, and hope in the future to have the technology and equipment to further reduce noise and vibration. Unfortunately, at present, there is little more that can be done to further reduce Tube noise. TfL continues to work alongside industry and academia to further understand noise and vibration and to trial new products and solutions.

 

Tube noise [9]

Question No: 2018/1549

Andrew Dismore

To what extent was noise pollution considered in the design and commissioning of the recent investment in new tube trains?

Written response from the Mayor

I continue to press TfL to carry on actively working with suppliers to innovate and develop new technology to improve noise levels across the network. For the next generation of Deep Tube trains (for use on the Piccadilly, Central, Bakerloo and Waterloo & City lines), Transport for London has included requirements for improved suspensions systems. This, along with track quality improvements, will optimise performance at the wheel-rail interface by ensuring the trains will be better suited to the infrastructure and operating environment of each line. This interface is the key determinant of noise and vibration on the Tube network.

 

Tube noise [10]

Question No: 2018/1550

Andrew Dismore

I have been trying for several months to arrange a site visit with Transport for London (TfL) engineers to places along the Northern Line that are suffering excessive noise; at the London Assembly Plenary meeting on your Environmental Strategy, you agreed that the new Deputy Mayor for Transport would also visit these locations with me. Will you now instruct TfL to stop prevaricating and arrange these visits?

Written response from the Mayor
I understand that Transport for London (TfL) officers have met with you and residents on a number of occasions to discuss noise issues from the Northern line.

The new Deputy Mayor for Transport is meeting with you this month to discuss the issue of Tube Noise, and TfL officers are in touch with your office regarding a further visit with residents around Kentish Town and Mornington Crescent.

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